1. Field of the Invention
The direct oxidation of organic sulfides to sulfones is a well known process, using common oxidizing agents such as peracids. However, when fluorine atoms are present close to the sulfide sulfur atom, and particularly if the fluorinated group is sterically hindered, the oxidation becomes more difficult. Such sulfides were reported by N. V. Kondratenko, et al., J. Org. Chem. USSR (translation), vol. 16, p. 1049-1054 (1980), to be oxidized to sulfones in moderately good yields by chromic anhydride or concentrated H.sub.2 O.sub.2 /trifluoroacetic acid/trifluoroacetic anhydride, both powerful oxidizing agents.
2. Technical Background
The instant invention, oxidation of fluorinated sulfides to sulfones using a combination of fluorine/water/aceto-nitrile as the oxidizing agent, yields the desired sulfones under mild conditions and in good yields.
The combination of fluorine/water/acetonitrile has been reported to epoxidize fluorinated olefins (U.S. Pat. No. 5,084,583), and to oxidize aromatic amines to nitroarenes, (M. Kol and S. Rozen, J. Chem. Soc., Chem. Commun., p. 567-568, 1991). No mention is made in either paper of oxidation of sulfides to sulfones.